Typical arrangements of components within present day digital computers may be illustrated by the well-known IBM-compatible personal computer (PC). Within a mechanical enclosure, commonly known as the “case”, there typically is a relatively large circuit board known as the “motherboard”. The motherboard has several sockets, known as “expansion slots”, into which smaller circuit boards may be plugged and through which the smaller circuit boards, known as expansion boards, may make contact with supply voltage and signal lines of the motherboard, thus becoming integral parts of the digital computer. Display adapters, network interfaces, modems, and the like are generally installed in computers as expansion boards; this imparts more flexibility of configuration than if those circuits' functions were integral to the motherboard.
Another class of components intended for discretionary installation in digital computers is storage devices, such as disk drives, compact disk read-only memory (CD ROM) drives, and the like. Storage devices are generally electromechanical in nature and thus have appreciable weight and bulk and thus do not lend themselves to being incorporated into electronic circuit boards, such as expansion boards. Therefore, a PC typically contains “drive bays” for accommodating such devices.
When adding electronic components on expansion boards to a computer to adapt it for certain applications, such as for telecommunications, it is often found that the electronics are of such bulk that there is not sufficient room for them or that the components must be crowded such that adequate cooling of them may not be attained.
Also, for applications such as telecommunications, voltages may be required that are not furnished within the computer, requiring an additional power converter unit which compounds the aforementioned space and cooling problems.
In addition, inserting cards in the motherboard requires powering down the computer and opening the case, which limits ease and flexibility of reconfiguration.
For applications such as telecommunications it is often necessary to make numerous external connections to the added circuit boards. This may prove difficult with boards installed in the expansion slots on the motherboards since they are contained inside the computer case and have very little exposed faceplate area. Component height is limited due to the typical pitch of the expansion sockets.
There have been attempts to solve these problems based on computers with large cases and large motherboards with bus extenders, but these solutions have proven inconvenient and expensive.
There is thus a need for a computer with economical provision for the insertion of a large volume-of expansion circuitry, without the necessity of powering down or dismantling the computer, and allowing easy connection of external cabling to the expansion circuitry.
It is thus an object of the present invention to provide an economical computer in which a large volume of expansion circuitry may be installed.
It is a further object of the present invention to provide a computer in which expansion circuitry may be installed without powering down, opening, or dismantling the computer.
It is another object of the present invention to provide a computer in which expansion circuitry including tall components may be installed.
It is a further object of the present invention to provide a computer in which external connections may easily be made to expansion circuitry.
It is yet another object of the present invention to provide a computer in which a large volume of circuitry may have access to air outside of the computer for cooling.
These and other objects of the invention will become apparent to those skilled in the art from the following description thereof.